This application claims the priority of German application 19910084.5, filed in Germany on Mar. 8, 1999, the disclosure of which is expressly incorporated by reference herein.
The invention relates to an actuating device for a vehicle seat with a seat back that can be folded forward into a deflected position to facilitate entrance and exit. The seat back can be folded forward around a pivot axis into a deflected position to facilitate entry and exit, to with the seat back being secured in its folded-back end position by bilaterally provided rotary drop latches that are synchronously remotely unlockable by a common actuating element and with a tension means arrangement being provided for remote unlocking.
In such an actuating device that can be found in German Patent Document DE 24 04 216 A1, the seat back of a vehicle seat is secured in its folded-back end position by rotary drop latches provided on both sides in the vicinity of fittings. At the upper end of the seat back is a manual lever by which the rotary drop can be remotely unlocked in synchronization by Bowden cables that run on both sides of the seat back. For this purpose, a transmission rod is provided in the upper area of the seat back by which the motion of the Bowden cables is synchronized when the manual lever is actuated.
Under unfavorable conditions, for example as the consequence of excessive lengthening of one of the Bowden cables, incomplete or unilateral unlocking of one of the rotary drop latches can occur so that the seat back can no longer be folded forward smoothly without any problems any longer into its deflected position. To ensure operating safety, a correspondingly higher maintenance expense must be paid.
An actuating device for a vehicle seat is known from French Patent Document FR 25 63 716 in which the seat cushion part can be secured in its folded-back end position by bilaterally provided rotary drop latches. The two rotary drop latches are rotationally coupled with one another by a connecting rod and unlockable remotely in synchronization by means of a common Bowden cable. The Bowden cable is connected with the back of the seat so that when the seat back is folded forward, the rotary drop latches are unlocked and the seat cushion part together with the seat back can be folded forward.
In German Patent Documents DE-AS 12 86 922 and DE-GM 18 24 238 an actuating arrangement is shown in which the rotary drop latches can be unlocked by a common manual lever provided in the area of the fitting between the seat back and the seat cushion part. When the manual lever is operated, the two rotary drop latches are unlocked in synchronization by actuating the manual lever by means of a rod including a connecting rod.
Finally, in the actuating arrangement known from German Patent Document DE 41 42 924 A1 both rotary drop latches can be unlocked remotely in synchronization by an associated Bowden cable.
A goal of the invention is to provide an actuating device which ensures a secure locking of the seat back to the seat cushion part with the rotary drop latches being released with reduced maintenance expense and higher operating safety.
This goal is achieved according to the invention by an actuating arrangement for a vehicle seat whose seat back can be folded forward around a pivot axis into a deflected position to facilitate entry and exit, with the seat back being secured in its folded-back end position by bilaterally provided rotary drop latches that are synchronously remotely unlockable by a common actuating element and with a tension arrangement provided for remote unlocking, wherein the rotary drop latches are rotationally coupled by a connecting rod and operable connected with the actuating element by a single tension strand, and wherein the rotary drop latches are rotationally coupled by a connecting rod and operably connected with the actuating element by a single tension strand, and wherein the rotary drop latches are mounted with their rotary drop axles on the seat cushion part and, in their locking position with the seat back folded back, each fit around an associated retainer structure of the seat back in a locking fashion.
Advantageous embodiments of the actuating device according to the invention together with advantageous improvements on the invention are described herein and in the claims.
The connecting rod ensures in simple fashion that both rotary drop latches operate in permanent synchronization under all operating conditions. Reducing the tension arrangement by one tension strand also contributes to operating safety since correspondingly less friction must be overcome when operating. In addition, the maintenance expense is reduced as well since the connecting rod requires no maintenance, by contrast with a cable.
By locating the rotary drop latches on the seat cushion part, the weight of the seat back can be advantageously reduced. In addition, no space is required in the seat back for the connecting rod.
When the actuating element cooperates through a Bowden cable and control mechanics with one of the rotary drop latches, the operating safety of the locking system can be increased in a simple manner. In particular, it can be ensured that the rotary drop latches can engage only under their spring loads when the seat back has reached its folded-back end position.
A lightweight yet very stable design is achieved by a U-shaped design for the rotary drop latches. Preferably, the loops cooperate with an associated retaining leg that is part of the supporting hardware of the seat back, required in any case.
As a result of the height adjustability of the supporting structure, a largely zero-play locking of the free leg ends by the loops can be achieved.
In an integral seat, the latching mechanics can be reinforced on the side that is subjected to a greater load in the event of a collision in simple fashion by making the loop on this side thicker.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.